Curved TV vs Flat TV

[The_Rev]

 

Out of curiosity, why get expensive HDMI cables?

Yes, it's to do with the capacity of the cable and the speed of the data transfer. The ones I have transmit up to 27 GBps - Ideal for 4k. The picture quality will always be the same, the cable capacity I believe dictates the frame rate available, so for the 4k Upscaler and the PS4 I went for the 2 for 1 on the premium cables, and then for the Sky box it doesn't really matter, Sky only supports upto 1080i anyway so there would be no benefit from having a top notch cable for that.

 

 

 

Are we up to HDMI 2.0 yet?   1.4 is the ubiquitous standard and I know that's where my TV is at, I know 1.4 struggles to go above 4k 30fps which leaves me wondering, will 2.0 take off or will everybody just switch to Displayport like PC gamers largely have? 

[DeadlyDirk]

No idea, my TV has one HDMI 2.0 input with the remaining two being 1.4, but I don't think it'll be fully in use until native 4k products are more mainstream as it where.

[dont_do_it_doug.]

I would wait another year for 4K personally. I certainly don't think it's 5 years away though, supply and demand will take off, 50 inch screens will become the norm in many homes and my god 4K is impressive at that size. I can tell the difference myself 3m away from a 42 inch and though I appreciate that at the moment it's not enough to justify the cost for me, as the price of the technology and production decreases so will the cost of the screens and as we know, everyone wants the best.    

 

4K is not a gimmick and it will happen. Soon. Just not today. 

[The_Rev]

I don't think it's a gimmick, I do think next year is too soon to expect a glut of content.  It's a chicken and egg thing really, content producers won't start making 4K video in significant quantity until 4K panel ownership hits a critical mass and of course there are plenty of people who won't buy a 4K panel until they feel like they are missing out.    

 

Maybe if you are the kind of person who buys a lot of Blu Ray discs then you will find yourself with things to watch in 12-18 months but if you aren't then I still see it being a while before we start seeing TV broadcast in 4K.  Maybe the 2018 World Cup. 

[PieFacE]

Netflix steam in 4k don't they? Also Sky will be providing a 4k service not before too long, certainly within 5 years, 1 or 2 probably. However, it will be on demand stuff.

[jim]

Netflix steam in 4k don't they? Also Sky will be providing a 4k service not before too long, certainly within 5 years, 1 or 2 probably. However, it will be on demand stuff.

Doubtful, Sky can't even do 1080p

[PieFacE]

http://www.techradar.com/news/home-cinema/new-4k-channel-hints-that-sky-s-uhd-service-is-close-1284630

I think they will. Also read an interview with someone at sky saying that 4k on demand isn't far away.

Edited June 18, 2015 by PieFacE

[ender4]

I would wait another year for 4K personally. I certainly don't think it's 5 years away though, supply and demand will take off, 50 inch screens will become the norm in many homes and my god 4K is impressive at that size. I can tell the difference myself 3m away from a 42 inch and though I appreciate that at the moment it's not enough to justify the cost for me, as the price of the technology and production decreases so will the cost of the screens and as we know, everyone wants the best.    

 

4K is not a gimmick and it will happen. Soon. Just not today. 

 

 

what if virtually everything someone currently watches is 'downloaded'  in 1080p (hypothetically speaking).

 

do we think 4k will start appearing online soon?

[The_Rev]

Netflix steam in 4k don't they? Also Sky will be providing a 4k service not before too long, certainly within 5 years, 1 or 2 probably. However, it will be on demand stuff.

 

 

Only a very small selection.  Season 3 of House of Cards shot filmed in 4k and the number of shows/movies being shot in 4K will only continue to grow.

There is 4K content out there and like I said earlier if you are the sort of person who likes to buy Blu Ray discs then we are probably reaching the point where it's not foolish to jump in.  I just happen to believe that most of us won't feel like they are missing out by not having a 4K screen for a while yet.  I bought a very nice 1080p set about a month ago when I could have gone for a 4K set. I don't regret my decision. 

[dont_do_it_doug.]

Ok. I give it till the end of 2016 before we see sky sports, movies etc being offered in 4K resolution along with the majority of saleable television shows and movies being shot in 4K. At that point buying a panel which "only" displays 1080p will be akin to buying a "HD Ready" TV 4/5 years ago.

[Kingman]

Ive had the Samsung UHD - 55HU8500 for about 7 months and its certainly far from a gimmick, No matter what position in the room the TV is truly stunning from every angle, Only hitch i had was that some channels appeared a more deeper red than others. It wasn't even noticed by visitors or the mrs but i could tell. 

 

After various tweaks i still couldn't eliminate it so ended up bringing in a firm that THX calibrated the set off a meter and laptop for about 4-5hrs. 

 

 

I posted something similar that with UHD you could sit as close as 0.5 metres from a 20-inch screen and 1.2 metres for a 100-inch screen. Of course these are just rough estimates but it gives you an idea of how optimum viewing distances is calculated. To calculate the best viewing distance for your TV, what you really need is a set of tables so you can check your TV's diagonal screen size and resolution, thus quickly working out how far away you need to sit. The problem here is that there are a number of different tables produced by manufacturers, retailers and industry bodies like SMPTE or THX. In terms of the recommendations of manufacturers, they tend to be the most conservative, recommending a viewing distance of 2.5 times the screen's diagonal width. So for a 50-inch screen the optimum viewing distance would be 125 inches or about 10 feet (3.18m).

However multiplying by a factor of 2.5 is more related to the optimum viewing distances recommended for a standard definition TVs and since high definition TVs have much higher resolution, you can in fact sit much closer. SMPTE (Society of Motion Picture and Television Engineers) recommends a viewing distance that is 1.6 times the diagonal width of the screen. This is generally regarded as idea for high definition TVs and so, using the same example, you would sit 80 inches or 6.6 feet (2.03m) from the screen.

THX however feel that the viewing distance should replicate the immersive cinematic experience as closely as possible. So they recommend a viewing distance that is 1.2 times the diagonal width of the screen. By sitting closer the screen fills more of your field of view and THX believe that high definition content has the resolution to handle these closer viewing distances. This means that using our 50-inch screen for a third time, the distance would be 66 inches or 5.5 feet (1.68m).n fact the THX calculations would actually work as a general estimate of viewing distances for Ultra HD TVs, especially when compared to the other guidelines. In fact when it comes to ultra high definition, you will need to sit quite close to your TV to fully benefit from the higher resolution, especially with screen sizes below 65 inches. Of course ultimately these are purely guidelines and there is no right or wrong answer. In fact even the industry bodies involved can't agree on a single solution, so ultimately it should come down to personal preference. 

 

As for UHD content its here and its vast, BT Sport’s 4K Channel starts on 1/8/15 with the Charity Shield being the first live game screened in UHD on the 2/8/15, Netflix’s commitment to 4K grows every month (Breaking Bad in 4K makes you wanna slap ya momma),  If UK netflix aint enough then switch settings to Netflix USA that has even more 4k content. Amazon also has its own 4k content channel and there is also availability of dedicated 4K promo channels from SES Astra and Eutelsat, and Hispasat is also available (Tune your 4k TV to 12441, V,   29500,  3/4,  DVB-S2,  8PSK) 

 

In Japan they are more or less skipping 4k and going straight to 8k, NHK has been working on 8K Super Hi-Vision for more than a decade, screened its first clip in 2001, and has tackled many of crucial technology issues along the way to make it a reality and will screen the 2020 Tokyo Olympics in 8k. 

 

Early adopters of UHD, could find their expensive new screens unable to handle broadcasts in a super-sharp format when they finally take off.

Screens of 3840 x 2160 (UHD) to 4096 x 2160 (4K) resolution are the first major resolution milestone reached since HD Ready and Full HD arrived almost a decade ago.

But due to a lack of global standards set out by regulating authorities and the United Nations, consumers who bought a 4K television in 2013, 2014, or even in the first half of 2015, may find it impossible to watch UHD sports when they are broadcast in the years to come.If you bought a set in 2013 and early 2014, then sorry, it won't do sport. It'll only go up to 25 frames per second (fps). If you bought a set last year, even a set in the sales this summer, this spring, then I'm sorry - it won't do High Dynamic Range, which gives you better, brighter pictures."

The problem is that many UHD televisions cannot support content broadcast at more than 25fps, a problem tied to the refresh rate and underlying hardware of the UHD screen panel. This is the speed used by almost all Hollywood films, so while they will play without a problem, broadcasters are yet to agree on what frame rates to use for sports, which are typically much faster and suffer from poor picture quality when played at low frame rates.

A suggested 100fps would be ideal for sports broadcasts. Higher frame rates require better HDMI cables going to 2.0a, but also improved hardware on both the transmitting and receiving ends of the signal, so a software update won't improve a television's frame rate. Samsung recognises the changing UHD landscape and offers the UHD Evolution Kit, a £400 device which plugs into 4K televisions from 2013 to give them the performance upgrade of a quad-core processor and HDMI 2.0 connectivity.

But because TV stations haven't yet decided on how to broadcast UHD content, there is no way of knowing if this kit will make older sets compatible with future broadcasts. Even if your tv has not got HVEC its already obsolete, Thus due to the 10 bit chip required especially for netflix 4k. most sets have an 8 bit chip. Ask this question when buying your 4k tv. Failling that just make sure it has HDR. 

 

PS 

 

Bluray 4k will be on the shelves for christmas, red-ray will be taking over the higher output resolution.

Edited June 19, 2015 by Kingman

[ender4]

oh wow, so the gist of that is to possibly not get 4k yet, but to wait another 6-12 months to get the good 4k for sports.

[Kingman]

Yeah you can buy now but just make sure the set has HDR for sports action and HEVC for channels like Amazon & Netfilx UHD, Along with BT's new UHD G5 set-top box from Humax, a Youview+ box

If peeps have got Samsung sets from mid/late 2013 they will probably get software updates to update there Evolution kits to Tizen and the new five-panel Smart Hub user interface. The update including HEVC and VP9 codecs so you can look forward to delighting in some glorious, buttery-smooth 4K/60p video action that will be required for fast moving sports. On the hardware front, the upgrade kit includes an octa-core processor, extra RAM, a new touch remote, and HDMI 2.0 ports with HDCP 2.2 

 

Do your research on the sets software and functions before you buy and make sure it has all the required specs above otherwise the set will not be Full 4k capable.

A bit like the first HD sets being sold off as HD-ready but were only 720 interlaced and not Full HD 1080 progressive till later stages of development. 

 

Go to richer sounds or similar for advice and guidance, or see a proper manufacture rep at john lewis or currys/pc world superstore. Be mindful of specification information from general staff at the latter two, One guy once try to push a 4k dvd player on me saying the player would upscale and the tv would also so it would now upscale twice. 

 

I almost hit him over the head with a near by roberts radio.

Edited June 21, 2015 by Kingman

[Kingman]

Update… 

 

If you're buying a new television this year then chances are you're after an Ultra HD TV. It's the new buzzword in TV tech and it can deliver sharper, crisper, high-fidelity visuals than possible at a measly 1080p.

 

Every manufacturer is now lining up to offer you a 4K TV. But where it was once almost a content-less gimmick, limited to showfloor showreels, there is starting to become more and more UHD movies and TV shows on offer from all over.

Ultra HD Blu-rays will be on sale by the holidays this year, Samsung offers a UHD content pack with its TVs and Netflix is now setup to deliver 4K content online to its premium subscribers. 

There are also a host of broadcasters testing out live UHD content too. They're even working on 8K broadcasts for the Women's World Cup this year!

 

Ultra HD is not just about that 3840 x 2160 resolution any more either.

With technologies such as Quantum Dot, OLED and HDR able to deliver your 4K movies with frankly stunning levels of picture quality there's a whole lot more to UHD than just 8.3 million pixels.

 

And it doesn't have to cost the earth to get on the Ultra HD rollercoaster either. 

Here is our choice for the best 4K TVs in the world today, from the wallet-busting 65-inch beasts to the best 48-inch TV we've ever seen. 

 

http://www.techradar.com/news/television/10-best-ultra-hd-4k-tvs-in-the-world-today-1198304

Edited July 18, 2015 by Kingman

[jjaacckk91]

Update…

If you're buying a new television this year then chances are you're after an Ultra HD TV. It's the new buzzword in TV tech and it can deliver sharper, crisper, high-fidelity visuals than possible at a measly 1080p.

Every manufacturer is now lining up to offer you a 4K TV. But where it was once almost a content-less gimmick, limited to showfloor showreels, there is starting to become more and more UHD movies and TV shows on offer from all over.

Ultra HD Blu-rays will be on sale by the holidays this year, Samsung offers a UHD content pack with its TVs and Netflix is now setup to deliver 4K content online to its premium subscribers.

There are also a host of broadcasters testing out live UHD content too. They're even working on 8K broadcasts for the Women's World Cup this year!

Ultra HD is not just about that 3840 x 2160 resolution any more either.

With technologies such as Quantum Dot, OLED and HDR able to deliver your 4K movies with frankly stunning levels of picture quality there's a whole lot more to UHD than just 8.3 million pixels.

And it doesn't have to cost the earth to get on the Ultra HD rollercoaster either.

Here is our choice for the best 4K TVs in the world today, from the wallet-busting 65-inch beasts to the best 48-inch TV we've ever seen.

http://www.techradar.com/news/television/10-best-ultra-hd-4k-tvs-in-the-world-today-1198304

So either spend £6-8k

The £1.2k looks more reasonable but has issues.

Or a screen too small at 40 in to really make the most of 4k. And at £650 still comfortably double the cost of HD at a similar size.

I'm still not entirely convinced on uhd as a concept, I think HD is good enough for the majority of uses/users. Its clearly still a way from true 4k for the masses at those prices though.

[Kingman]

Not really, all you need to know...

 

Update: Don't get scammed by 4K-compatible HDMI cables! Check out the "What kind of cables will I need" section below for more information. 

4K: Everyone wants it and no one knows why. It's the hottest techy buzzword of 2015, and it's a technology that's rewriting the rulebook when it comes to image quality.

It affects not just the world of 4K TV and cinema, but also cameras and image capture, smartphones and tablets, computer monitors and PC games - practically anything that displays images or records video.

4K TV sets are now available from most of the major TV manufacturers - i.e. Sony's impossibly slim Android TV, LG's OLED or Samsung's SUHD series of TVs - but they're merely the tip of a very cool technology iceberg.

So what, we hear you ask, is 4K really all about?

What is 4K?

The headline fact is simple and dramatic: 4K Ultra HD TVs (also known as UHD TVs) deliver four times as much detail as 1080p Full HD, that's eight million pixels compared to two million pixels.

What that means in terms of potential image clarity is more fine detail, greater texture and an almost photographic emulsion of smoothness. 

But this is just for starters. Prior to a roll-out of TV services, broadcasters are working out what else they can upgrade under the 4K banner. In the UK, a working group chaired by the BBC and BSkyB are mulling over every possible tweak, from higher frame rates to greater contrast and a wider colour spectrum. Some of the biggest names in the video industry including Samsung, LG and Sony have split-off to form another group called the UHD Alliance, which will work to set standards for the new format. 

But talk to the engineers steering this 4K broadcast bandwagon and they'll tell you everything spec-wise is up for grabs. If this indicates to you that the 4K standard is anything but set in stone, you'd be correct.

Ultra HD is going to be a work in progress for years to come, but that doesn't mean you should wait for the dust to settle before improving your image.

• What's new with 4K TVs? The IHS predicts there will be almost 1 million 8K televisions sold by 2019.

Difference between Ultra HD and 4K

Technically, "Ultra High Definition" is actually a derivation of the 4K digital cinema standard. However while your local multiplex shows images in native 4096 x 2160 4K resolution, the new Ultra HD consumer format has a slightly lower resolution of 3840 X 2160.

This is one reason why some brands prefer not to use the 4K label at all, sticking with Ultra HD or UHD instead. However, the numerical shorthand looks likely to stick. As a broad brush label it's so much snappier!

Why should I care about 4K Ultra HD?

There are many reasons why 4K should make you rethink your next TV purchase (actually, there are eleven and you can read about them here), not all of them immediately obvious.

Photographers who routinely view their work on an HD TV are seeing but a fraction of the detail inherent in their pictures when they view them at 2160p.

A 4K display reveals so much more nuance and detail – the difference can be astonishing. While 3D has proved to be a faddish diversion, 4K comes without caveats. Its higher resolution images are simply better.

The higher pixel density of a 4K panel also enable you get much closer without the grid-like structure of the image itself becoming visible –this means you can comfortably watch a much larger screen from the same seating position as your current Full HD panel. Currently all available 4K Ultra HD TVs are in excess of 50-inches. 

Projectors

While 4K UHD TVs are on the fast track, the same can't be said for video projectors. Only Sony offers 4K models, the high-end quasi pro VPL-VW1100ES and the home cinema friendly VPL-VW500ES.

Currently there's no consumer 4K solution for LCD, D-ILA or DLP projectors, although that's likely to change in 2015, when Texas Instruments is expected to begin shipping its first 4K DLP chipset for home hardware.

How expensive is an Ultra HD TV?

The first wave of 4K TVs were large, really large. Both Sony and LG launched with 84-inch panels, the KD-84X9005 and 84LM960V respectively.

Consequently, they were saddled with price tags in excess of £20,000/$30,000. Not to be outdone, Samsung weighed in with the 85-inch S9 at £35,000/$55,000, clearly aimed at footballers and oligarchs!

However, prices have fallen dramatically as screen sizes have shrunk and brands have predictably embarked on a tit for tat price war. You'll now find 4K TVs for less than $1000, though we'd encourage you to be careful when choosing one - a 4K resolution won't necessarily give you a better picture if the processing electronics behind the panel are bad.

Generally speaking, a market-leading 65-inch 4K TV like the Sony KD-65X9005B will set you back a little over $3,500/£3,000... and they're getting cheaper.

So how small will 4K Ultra HD screens get?

In the short term, screen sizes are likely to stabilise at 55-inches and upwards. That's because as the screen size shrinks the advantage of having such a pixel dense display starts to diminish. There's also an irrefutable relationship between screen resolution and viewing distances.

While seating will vary from home to home, generally speaking a large 4K TV will provide an upgrade for a smaller 1080p screen. However, the 4K resolution will ultimately be about more than just definition.

High frame rate UHD broadcasting could have an even greater impact than resolution when services begin – and the benefits of HFR are not restricted to larger screen sizes. When this second generation 4K UHD breaks cover, expect high-frame rate 4K TVs to drop further down the size scale. 

How far should I sit from a 4K TV for the best picture?

4K Ultra HD is a much more intimate viewing experience than Full HD. In many respects, the best way to view 4K is analogous to the way we view films in a cinema. Old style cinemas were shoe-box shaped and most patrons sat typically 3-5 screen heights away, because that was the most comfortable viewing distance.

Contemporary cinemas are wider, and now the optimum viewing distance is 1.5 screen heights back. From this vantage point you can take in all the visual information that's available and comfortably fill your field of vision. Translated to the home, that makes the most comfortable distance to view a 65-inch 4K screen approx. 1.5m. Of course, in many homes that simply isn't practical. Consequently, a large 4K screen is probably best viewed at a distance of between 2-3m; time to rearrange your furniture?

 

If you have the bandwidth, you can now watch some Netflix shows in Ultra HD 4K

 

Is 4K OLED on its way? 

OLED - organic light emitting diodes - have been around for some time, but producing big screens using this technology has proven to be prohibitively expensive, something which has blighted the chances of OLED televisions becoming mainstream.

Which is a real shame, because OLED technology can be stunning - with vibrant colors, deep blacks and bright whites. 

And obviously some companies agree because the likes of LG are labouring away to bring OLED to 4K televisions. "I believe the price and yield rate will be higher immediately and the price will be down," Mr K I Kwon, president of LG Electronics UK, told TechRadar recently. 

So, although LG's next 4K OLED television will remain too expensive for mass market, we shouldn't rule out OLED as a big player in the next generation of our televisions just yet.

4K TV channels

There are currently no 4K TV channels being broadcast. But in July 2014 the DVB Steering Board approved the DVB-UHDTV Phase 1 specification, allowing for over-the-air transmission of 3840x2160 resolution pictures at 60Hz and promising much improved colour depth with 10 bits per pixel rather than 8.

The standard is expected to be ratified by the ETSI shortly, which is likely to open the floodgates for broadcasters to start launching Ultra HD TV channels.

The main problem with this new standard is that current TVs and set-top boxes will be incompatible, so you'll need to buy new gear to make use of it. You can read more on this in our news story.

What 4K content is available for me to watch?

As of April 2014, Netflix became the first big name to deliver 4K content to the home. When you open the Netflix app on a 4K TV, 4K content will stream automatically where it's available. From the start, that's just House of Cards Season 2, but don't worry - there's LOTS more 4K content ready to be piped into your home.

• Read: Home entertainment in 2015: what you need to know

YouTube offers a nascent 4K channel, but you'll require a powerful PC with a 4K capable graphics card, of which there are few that make economic sense.

But the lack of native 4K isn't quite the big deal you might at first imagine. The truth is today's Ultra HD screens do such a remarkable job with 1080p content that you almost certainly won't feel shortchanged. Rather than just linearly scale, big brand sets utilize all manner of database interpolation to upscale images, and the results are spectacular. 

To take advantage of this, Sony has released a selection of Mastered in 4K branded Blu-rays. These are in fact standard 1080p Blu-ray discs, albeit ones based on the best available transfers which take full advantage of available disc capacity. They have also been mastered with a wider colour range than standard Blu-ray platters. 

A 2160p upgrade on the Blu-ray standard is inevitable, of course, which will allow for true Ultra High Definition movies to be sold on disc.

Sony meanwhile has rolled out a download service in the USA for owners of Sony 4K TVs – however there's no sign of that arriving in Europe just yet.

What kind of cables will I need for 4K?

The two standard cables you're most likely to use are either a standard HDMI or if you're connecting a PC to a Ultra HD monitor, DisplayPort. 

HDMI cables now come in two flavors: 1.4 and 2.0. HDMI 1.4 cables are the super inexpensive kind found at the dollar bin of your local electronics retailer. They're cheap and can output a 3820x2160-resolution at 30 frames per second. HDMI 2.0 is the latest spec and can output video at Ultra HD resolution at 60 frames per second. (But more on that below!)

The other type of cable you can use is DisplayPort. DisplayPort carries 4K image and audio signal from most high-end graphics cards to monitors without any noticeable artifacts or delays. 

How important is HDMI 2.0 to 4K Ultra HD?

HDMI 2.0 is the latest iteration of the HDMI specification. While the existing HDMI 1.4 standard can deliver 4K video, it's limited to 30 frames per second (or 30Hz). While this is fine for most movies, broadcasters are looking for higher frame rates for TV. 

HDMI 2.0 increases bandwidth up to 18Gbps and supports 4K Ultra HD at 50/60 fps, with 12-bit 4:2:2 colour (you don't need any special cables for HDMI 2.0 interconnectivity, any current high-speed cable will work). However, only Panasonic currently offers an HDMI 2.0 compatible 4K TV, in the shape of the TX-L65WT600.

So where does that leave the remaining first generation 4K sets? Well both Philips and Samsung, whose 4K panels are coupled to separate connection boxes, say they'll simply introduce new tuners which owners can upgrade to.

Sony and others are looking to implement a firmware fix; by shedding colour sub pixels they reckon they'll be able to fit high frame-rate 4K down a HDMI 1.4 pipe, most likely with 8 bit 4:2:0 colour. How visible this kludge will be remains to be seen. For what it's worth, we've seen JVC's 4K e-Shift3 projectors running 4K at the same colour resolution, and they look spectacular so the omens are good.

I've heard Netflix is going to start streaming in something called HDR. What is that?

HDR, UHD, OLED ... there's no shortage of acronyms in home entertainment. 

HDR, or high dynamic range, is a concept borrowed from digital imaging which combines three images - one with normal lighting, one with underexposure and one with overexposure - to give more contrast to an image or video. Netflix will be the first content provider to release HDR video in 2015. 

You won't necessarily need a UHD screen to get it, but to really see a difference in picture quality you'll want to step up to the higher resolution. 

Quantum Dot sounds like theoretical physics

It does indeed. But unlike some problems in theoretical physics, the solution is already here. Quantum Dot displays (QD for short) are simply LED panels with a thin film of nano-crystals in between the backlight and the display. Manufacturers like LG and Sony claim that this increases color depth by around 30% without adding extra pixels or implementing a wacky algorithm to digitally manipulate the display.

We went hands on with a few QD panels at CES 2015, including the LG UF9400 Quantum Dot 4K UHD TV and Samsung SUHD Curved TV, which uses a variation of Quantum Dot. We liked what we saw, mostly, and especially on the Samsung SUHD. The LG had some issues with oversaturation ... but that may be fixed by the time the TV comes to market in Q2 2015.

Hang on, what about 8K?

If 4K offers four times the resolution of Full HD, then 8K will deliver 16 times the definition. 8K screens comprise a staggering 33 million pixels.

This is an order of magnitude beyond any display technology currently available, and only one broadcaster, Japanese state owned NHK, has publically said it intends to commercialise the technology. 

Also known as Super Hi-Vision, a number of 8K trials have been conducted, including acquisition at the London 2012 Olympics. NHK has since pledged to shoot and transmit the 2020 Tokyo Olympics in the format.

Of course, bringing 8K to market is a formidable technical challenge. As with 4K, HEVC, is currently favoured as the best compression technology for the job.

However, because the benefits of 8K image definition only really become apparent on screens 84-inches and larger, the format is not seen as a commercially viable platform by most broadcasters and TV manufacturers. If you're waiting to jump from Full HD to 8K, you could be kicking your heels for quite some time.

So should I buy a 4K set now or should I wait?

It depends. If you want the absolute best TV you can get right now and don't mind paying a premium for it, it's a 4K set. If you're buying from one of the top tier manufacturers, you're going to get a good product that's reasonably future-proofed. As we said before, the sets look great. However, don't expect to be watching most of your video content in 4K for another two to three years. And make sure any set you buy has HDMI 2.0 ports (the first wave of 4K TVs used the previous HDMI 1.4 standard).

On the other hand, if you're price sensitive or want to wait until the content side of the equation is a bit more solved, it absolutely makes sense to wait. You're not missing out on much at the moment. There are incredible values to be found in generously-sized 1080p sets right now. And 4K sets are only going to get cheaper.

http://www.techradar.com/news/television/ultra-hd-everything-you-need-to-know-about-4k-tv-1048954